Ms McCabe secretly planned to propose to her girlfriend, and organised for a friend to pretend to take a photo of the couple but to video the moment instead.

As the two women posed together, Ms McCabe held Ms Gillaspie's hands and spoke to her quietly. She then got down on one knee and produced a box with an engagement ring inside, which she'd been hiding behind her.

A thrilled-looking Ms Gillaspie jumped up and down with excitement before running to get something out of her bag.

"What are you doing?" a confused Ms McCabe can be heard asking.

The couple erupted into laughter when Ms Gillaspie produced her own ring box - she had planned to propose during the very same zoo trip.

Ms Gillaspie posted the video of their simultaneous proposal to Facebook, where it has received more than one million views.